/*! ========================================================================
** Extended Template and Library
** Mutex Abstraction Class Implementation
**
** Copyright (c) 2002 Robert B. Quattlebaum Jr.
**
** This package is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License as
** published by the Free Software Foundation; either version 2 of
** the License, or (at your option) any later version.
**
** This package is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
**
** === N O T E S ===========================================================
**
** This is an internal header file, included by other ETL headers.
** You should not attempt to use it directly.
**
** ========================================================================= */

#ifndef __ETL__RWLOCK_H_
#define __ETL__RWLOCK_H_

_ETL_BEGIN_NAMESPACE

class read_write_lock : private Mutex
{
public:

    read_write_lock()
    {  }

    ~read_write_lock()
    {  }

    // Exception-safe read-lock class
    class read_lock
    {
        read_write_lock *_mtx;
    public:
        read_lock(read_write_lock &x): _mtx(&x)
        {
            _mtx->lock_read();
        }
        ~read_lock()
        {
            _mtx->unlock_read();
        }
        read_write_lock &get()
        {
            return *_mtx;
        }
    };

    // Exception-safe write-lock class
    class write_lock
    {
        read_write_lock *_mtx;
    public:
        write_lock(read_write_lock &x): _mtx(&x)
        {
            _mtx->lock_write();
        }
        ~read_lock()
        {
            _mtx->unlock_write();
        }
        read_write_lock &get()
        {
            return *_mtx;
        }
    };

    void lock_read(void)
    {
        lock_mutex();
    }

    void lock_write(void)
    {
        lock_mutex();
    }

    bool try_lock_read(void)
    {
        return try_lock_mutex();
    }

    bool try_lock_write(void)
    {
        return try_lock_mutex();
    }

    void unlock_write(void)
    {
        unlock_mutex();
    }

    void unlock_read(void)
    {
        unlock_mutex();
    }
};

_ETL_END_NAMESPACE

#endif